Distillation, Observed
by Nightfall Rising
Summary: A study in camouflage. It's the best teachers whose students grow past them. Or: Horace knows the story of the moth.


**Disclaimer:** profitless fanwork  
(also up on AO3)

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Horace Slughorn knew the story of the moth. The air of his Britain was strangled with particulate matter, soot and poison and the bottoms of its people's lungs, and owls plucked bright insects off blackened bark, out of thick, grey air. Get out into the green, his father told him. Trade the trees' breath for yours; a man needs good air to think proper. Breathe trash, and it's in your lungs, in your blood, filling up your brain, passing through your heart and smearing the walls till they choke.

Horace went into the green, took a clean breath, looked around with clear eyes, and found a thousand small lives, some greater, all of use.

Now he's getting on, and his world is grey. He trades his air with, not flashing leaves, but the slow pulse of bare stone. It's blue slate, the sleekened surface of grainy granite and its sparkling mica, it's veined marble that surrounds him. Damp as life, it pulls the poison he makes out of him, out of his cauldrons, and into mossy patches, filtering back pure air, smelling of earth and rain.

Oh, the stones of Hogwarts live, and the dungeons have breath, but it's a breath that pulls his bones, not his ears. Not like the telltale emptiness from behind his biggest, blackest, iron-belly cauldron.

"A silencing spell's no substitute for good, honest stealth, m'boy," he observes to no one in particular. "Not when I know where the drips ought to be."

Silence.

Silence.

Drip.

Drip.

Drip.

Emerges from behind his rusty dragon the tip of a nose, a badly set bridge, a lock of hair lightened and weighted with dark dust, a shadowed face too sharp even for a little serpent. This year's piece of awkwardness, landed in his nest, black cloak puddled in a shadow, faded, mismatched clothes disappearing into the walls.

He waits for an explanation. Embarrassment, defiance, a plea of ignorance for the hour, protestations of innocence, a trumped-up question or request. What he gets is a small body settling beside him at the preparations bench, glossy black eyes fixed on his hands, drilling through him, and silence.

When the rhythm of a knife joins his, his mouth opens in admonishment that's mostly for himself, his inattention, but partly for the waste of ingredients that'll want paying for. But the boy, in his shabby clothes, is cutting air.

Putting his hands over smaller ones, he adjusts the grip, shows him the angle, the weighty love of a sharp point for the cutting board, the light-hearted stroke back towards a narrow chest. He calls for a house elf, asks for a basket of cabbages. Conscientious strokes become, over months, a steady flash of blade, ripped leaves turn to true-sliced shreds, cauldrons shine and small arms tighten, authors mentioned in passing turn up in essays, and he sees thin hands twist crisply from time to time, when in thought, as though plucking again the leaves that stain their fingers.

«  
(≈≈)

Horace Slughorn has heard himself compared to a sedentary spider, playing the cords of his web like a dulcimer, tapping down the lines until plump baskets in gay spellophane shiver their way back to him, sweet and rustling. Horace preferrs butterflies to spiders, those blithe little catalysts, stirring the shape of distant storms. The baskets are always appreciated, but there's nothing like sliding a name into its proper place, nothing like seeing an old favor paid back a thousandfold, nothing like a visit from an old student.

Nothing, nothing in the world, nothing ever like a visit from this student.

Nothing sweet, nothing promising, just hollowed cheeks, vacuum eyes, stained hands strained nearly to bare bone, the taut thrum of desperation dissolving away into the cool pores of the dungeon. Not his clothes faded now, no, not with those patrons, only his face grey over set bones of stark dread.

A long silence, scented steam rising from pretty cups too delicate for rawboned fingers, too small for pudgy ones. The flash of knives, the scrape of ladles and bubbles of magic breaking hot into the air, and finally scouring death sits placid, shimmering blue in the depths of its bright bronze cauldron, pages of looping shorthand beside it. It will take him months to deconstruct and rebuilt into a counteragent, he knows. Months, even with its recipe sitting beside it, as his children learn how to spin an essay and brave, foolish men and women die in agony every day.

Siphoning his poison into sampling vials, his protégé says, with crisp politeness he never came to school with, "Please resign."

Steam curls and vials clink.

"You don't want much, laddy, do you."

"Doesn't matter what I want." Prompt. Midnight eyes, moonless, starless, spinning him away with them into the bitter, sucking void. "You will. Because I've come to ask."

No more needs saying, not here in these dungeons, and so when he retires it's unthreatened and unbroken, with the dark unnamable so pleased with his ready cooperation that he's able to brew his counteragents in peace and unobserved, and slide them home to his old friend and to the Aurors. From the grey stones under Hogwarts, as Horace's greatest mistake curses and fumes from without and seeks the author of his thwarting, comes only silence and the occasional basket, death wrapped carefully under the pineapple, in papers that blossom with recipes in a crabbed hand by the light of a salty-wicked candle, sometimes entire days before it strikes.

«  
(≈≈)

Horace Slughorn knows the lesson of the snake, and it grieves him to see that of all his colleagues, most new only again, only the key-keeper glistens proud in a fresh skin. He's heard the legend of the yearly applications for a cursed post, and he expects triumph. Instead he gets resentment, and that only infrequently, when hollow black eyes can tear themselves from a brittle black hand. Small burdens of the House creep slowly onto his shoulders, and with them tales of unprecedentedly long Defense readings, fill-in-the-blank tests, barely structured classes, and no essays. His dungeons are never his own, a dark shadow standing always beside him, grim and silent but for the quiet sizzle of power on the boil, and the steady flash of a dancing knife.

Albus asks his patience and sets small children on him and ignores his fear. Albus reeks of unguents and herbs. Albus smells just like the workroom that ought to be his again.

They're both substitutes, he thinks, both just covering classes, and forgets the danger of using words to speak to this boy. He's told to mind his own business if he knows what's good for him, and he listens, oh, he listens, and he minds. Albus mouths trust, and Albus falls.

The knife of a face his gaze stutters over, one evening in the Leaky, is ash-pale, pared down into something so raw and bleak as to be unreadable, his mind telling him 'impassive' in self-preservation before his eyes catch up. He looks like a day-laborer, unremarkable, one of many at his table, and Horace wonders what that young man he protects, so unfortunate in all ways, thinks of all this.

Their eyes catch, and Horace is so strongly impelled to turn him in or break his sorry neck that he leaves his shopping in the cloakroom, on the hook of the transfigured overrobes that smell of misdirections and protections. Horace takes a certain measure of pride in his suggestibility, but he resents being taken for a puppet or a dupe.

«  
(≈≈)

Horace Slughorn is a better student of the mole than the chameleon, but he's not the only grown serpent in the castle these days. To his great relief, the bloated creatures that used to be his children remember and regard him as no more than a smarmy, oiled-up, sugar-coated old bear of very little brain, and that part he can play to perfection.

He teaches his classes, fair and unhurried, and attends to the few children, mostly younger, who find their way to his office door with their problems, instead of to the gargoyle staircase. He turns a blind eye to the politics and the guerilla tricks, and buries himself in research instead of making invitations. The dungeons are cold without his club to warm him, but those whose exclusion would draw attention to his sympathies are the very ones he cannot bring himself to flatter. It's another relief, a strange and unexpected relief, to find that his utilitarianism has limits. He knows who would be glad, but doesn't bother deciding whether he cares.

One day, as he pretends not to have noticed an ugly prank on one of his uglier-minded students, a darkly clipped voice from behind takes all the points he should have, and more, and an unrepentant Hufflepuff is sentenced to a night's frolic in a dark forest with the most solicitous of guardians.

All quite usual till that point, even to what the little 'Puff no doubt thinks is fortuitously mistaken, accidental leniency. "Let the oversized clod take the detentions," they'd been told. "He does less skilled labour than anyone but Filch, and Filch has served this school well, and doesn't deserve to be saddled with noisome, sullen, misbehaving brats after hours as well. He'll tell you he's anxious to help, but he's getting older, and one day they may realize he doesn't have a wand. Anyone who wishes to cover for him is free to cater to his wishes, of course."

All quite usual, until he finds himself slammed against the walls of his own skull by black holes in a still face. "Perhaps I should have given Carrow the House and had done with it," he's informed in tones of frozen courtesy, "if you're not going to look after the little brats."

Albus fell, but Albus lived faith.

Horace issues not invitations but summonses, and explains to his colleagues that in his opinion some of the students could use a little help in adjusting to the new tone of the school. If these meetings involve more sweets than sermons, more murtlap than menace, well, the Carrows don't have to know that. They're unlikely to find out, with even his Gryffindor guests learning a thing or two about the fine old art of not getting caught.

He begins to visit the gargoyle stairs himself, bringing papers to sit and grade quietly, or the peer-reviewed _Monthly Stirrings_ to discuss over tea. Sharing, once, an extract from an essay particularly ripe for mocking, he's met with silence, and looks up to see his boy ramrod-straight in the ornate chair, face slackened in quiet sleep, looking very nearly his right age. He thinks his heart will wring itself to shreds in pity and horror—sleeping, right in front of him, the very one of his own, _his Slytherins,_ who best knows better—and begins to come every evening he isn't meeting with shorter students.

«  
(≈≈)

Horace Slughorn knows the story of the moth, and when a black tomb is laid next to the white, he brings from the bones of the castle milky blue slate to change the stone of it with. He wouldn't wear black anymore, Horace is sure. Not now the air's clearing.

[fin]


End file.
